From d6195a6a2c247515d5832debb51c03a74dc3f8f6 Mon Sep 17 00:00:00 2001 From: Arnaldo Carvalho de Melo Date: Mon, 13 Feb 2017 16:45:24 -0300 Subject: perf evsel: Inform how to make a sysctl setting permanent When a tool can't open counters due to the kernel.perf_event_paranoit sysctl setting, we inform how to tweak it to allow the operation to succeed, in addition to that, suggest setting /etc/sysctl.conf to make the setting permanent. Suggested-by: Ingo Molnar Cc: Adrian Hunter Cc: David Ahern Cc: Jiri Olsa Cc: Namhyung Kim Cc: Wang Nan Link: http://lkml.kernel.org/n/tip-4gwe99k4a6p12d4u8bbyttj2@git.kernel.org Signed-off-by: Arnaldo Carvalho de Melo --- tools/perf/util/evsel.c | 4 +++- 1 file changed, 3 insertions(+), 1 deletion(-) (limited to 'tools/perf/util') diff --git a/tools/perf/util/evsel.c b/tools/perf/util/evsel.c index 04e536ae4d88..cd2fb42e5dd4 100644 --- a/tools/perf/util/evsel.c +++ b/tools/perf/util/evsel.c @@ -2469,7 +2469,9 @@ int perf_evsel__open_strerror(struct perf_evsel *evsel, struct target *target, " -1: Allow use of (almost) all events by all users\n" ">= 0: Disallow raw tracepoint access by users without CAP_IOC_LOCK\n" ">= 1: Disallow CPU event access by users without CAP_SYS_ADMIN\n" - ">= 2: Disallow kernel profiling by users without CAP_SYS_ADMIN", + ">= 2: Disallow kernel profiling by users without CAP_SYS_ADMIN\n\n" + "To make this setting permanent, edit /etc/sysctl.conf too, e.g.:\n\n" + " kernel.perf_event_paranoid = -1\n" , target->system_wide ? "system-wide " : "", perf_event_paranoid()); case ENOENT: -- cgit v1.2.3